Problem: $q + 9r + 3s - 9 = -7r - 10s - 6$ Solve for $q$.
Combine constant terms on the right. $q + 9r + 3s - {9} = -7r - 10s - {6}$ $q + 9r + 3s = -7r - 10s + {3}$ Combine $s$ terms on the right. $q + 9r + {3s} = -7r - {10s} + 3$ $q + 9r = -7r - {13s} + 3$ Combine $r$ terms on the right. $q + {9r} = -{7r} - 13s + 3$ $q = -{16r} - 13s + 3$ Isolate $q$ $q = -16r - 13s + 3$ $q = \dfrac{ -16r - 13s + 3 }{ {1} }$